Midwest Industries Handguard, Fits HK SP89 and Clones, M-LOK Compatible, Mil-Spec Top Rail, Black MI-SP89M The Midwest Industries M-LOK Handguard for the HK SP89/SP5K adds tactical modularity to the classic subgun design. It is constructed of 6061 aluminum with a hard coat anodized finish" and features M-LOK mounting slots along its length for accessories. It comes with one 5-slot M-LOK accessory rail. This rail is a slim 1.6" in diameter and weighs a scant 2.6 oz. It is compatible with the HK SP89" SP5K" SP5K-PDW and similar clones. Midwest Industries is a proven leader in the firearm industry. Made in the USA" focusing on the small details to make your rifle platform better.